/*
 *  Copyright 1999-2019 Seata.io Group.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package io.seata.server;

import io.seata.common.util.IdWorker;

/**
 * The type Uuid generator.
 *
 * @author sharajava
 */
public class UUIDGenerator {

	private static volatile IdWorker idWorker;

	/**
	 * generate UUID using snowflake algorithm
	 * @return UUID
	 */
	public static long generateUUID() {
		if (idWorker == null) {
			synchronized (UUIDGenerator.class) {
				if (idWorker == null) {
					init(null);
				}
			}
		}
		return idWorker.nextId();
	}

	/**
	 * init IdWorker
	 * @param serverNode the server node id, consider as machine id in snowflake
	 */
	public static void init(Long serverNode) {
		idWorker = new IdWorker(serverNode);
	}

}
